1. Field of the Invention
The present invention relates to an ink temperature controlling mechanism of an inkjet printer, and particular to a technique for increasing an effect of cooling inks whose temperatures have become higher.
2. Description of the Related Art
As described in Japanese Unexamined Patent Publication No. 2004-276486, a temperature range for guaranteeing the ink performance is specified for an inkjet printer for the purpose of obtaining a better printing result. In general, while an inkjet printer carries out a printing operation, the inkjet printer generates heat around its inkjet head. For this reason, when the printer performs printing, the temperatures of respective inks increase. In addition, when the ambient temperature is high, the temperatures of the inks rise as well.
To avoid adverse effect of the ink temperature rise, there have been practically-used an inkjet printer of ink-circulation type including a cooler configured to cool inks with the temperatures increased due to a printing operation and the like. Such an inkjet printer of ink- circulation type which circulates inks is described in Japanese Unexamined Patent Publication No. 2006-088575. The cooler cools the inks by use of a Peltier element (device), a heat sink, a fan or the like.
Once the temperatures of inks become higher than the temperature range for guaranteeing the ink performance, the printing operation is suspended because the higher ink temperatures may cause the printer to fail to maintain the printing quality or may adversely affect the operation of the printer. For the purpose of avoiding the suspension of the printing operation, it is necessary to improve the performance of the cooler. Nevertheless, the performance improvement requires the cooler to be constructed in a larger size, or the costs to be increased. In addition, the improvement of the performance of the Peltier element increases the electric power consumption during operation.